Sensor Based Power Switch Control Method and Sensor Based Power Switch Method Capable of Fast Turning on Power Switches

Abstract

A sensor based power switch control method includes setting a maximum inrush current, turning on at least one first power switches for charging a loading circuit from a high voltage terminal through the at least one first power switches, sensing a first charging current of the at least one first power switches being turned on by a first sensor, and turning on at least one second power switches for charging the loading circuit from the high voltage terminal through the at least one second power switches when the first charging current starts to drop.

What is claimed is: 
     
         1 . A sensor based power switch control method comprising:
 setting a maximum inrush current;   turning on at least one first power switches for charging a loading circuit from a high voltage terminal through the at least one first power switches;   sensing a first charging current of the at least one first power switches being turned on by a first sensor; and   turning on at least one second power switches for charging the loading circuit from the high voltage terminal through the at least one second power switches when the first charging current starts to drop.   
     
     
         2 . The method of  claim 1 , wherein the first charging current is smaller than the maximum inrush current. 
     
     
         3 . The method of  claim 1 , wherein after the at least one first power switches are turned on for charging the loading circuit from the high voltage terminal, the first charging current is increased to approach the maximum inrush current. 
     
     
         4 . The method of  claim 3 , wherein after the first charging current is increased to approach the maximum inrush current, a first voltage gap between the high voltage terminal and the loading circuit starts to drop. 
     
     
         5 . The method of  claim 4 , wherein after the first voltage gap between the high voltage terminal and the loading circuit starts to drop, the first charging current starts to drop. 
     
     
         6 . The method of  claim 1 , wherein after the at least one second power switches are turned on for charging the loading circuit from the high voltage terminal, the first charging current is increased to approach the maximum inrush current. 
     
     
         7 . The method of  claim 6 , wherein a total inrush current of charging the loading circuit is controlled to approach the maximum inrush current by the first charging current. 
     
     
         8 . The method of  claim 1 , further comprising:
 sensing a second charging current from the high voltage terminal to the loading circuit by a second sensor; and   turning on at least one additional power switch when the second charging current starts to drop.   
     
     
         9 . The method of  claim 1 , further comprises:
 generating a first message for turning on the at least one first power switches by the first sensor; and   generating a second message for turning on the at least one second power switches by the first sensor.   
     
     
         10 . A sensor based power switch control method comprising:
 turning on at least one first power switches for charging a loading circuit from a high voltage terminal through the at least one first power switches;   sensing a first voltage gap between the high voltage terminal and the loading circuit; and   turning on at least one second power switches for charging the loading circuit from the high voltage terminal through the at least one second power switches according to the first voltage gap.   
     
     
         11 . A sensor based power switch control system comprising:
 a power control circuit;   a first sensor coupled to the power control circuit;   at least one first power switches coupled to the first sensor; and   a loading circuit coupled to the at least one first power switches;   after the maximum inrush current is set, the at least one first power switches is turned on for charging a loading circuit from a high voltage terminal through the at least one first power switches, the first sensor senses a first charging current of the at least one first power switches being turned on, and when the first charging current starts to drop, at least one second power switches is turned on for charging the loading circuit from the high voltage terminal through the at least one second power switches.   
     
     
         12 . The system of  claim 11 , wherein the first charging current is smaller than the maximum inrush current. 
     
     
         13 . The system of  claim 11 , wherein after the at least one first power switches are turned on for charging the loading circuit from the high voltage terminal, the first charging current is increased to approach the maximum inrush current. 
     
     
         14 . The system of  claim 13 , wherein after the first charging current is increased to approach the maximum inrush current, a first voltage gap between the high voltage terminal and the loading circuit starts to drop. 
     
     
         15 . The system of  claim 14 , wherein after the first voltage gap between the high voltage terminal and the loading circuit starts to drop, the first charging current starts to drop. 
     
     
         16 . The system of  claim 11 , wherein after the at least one second power switches are turned on for charging the loading circuit from the high voltage terminal, the first charging current is increased to approach the maximum inrush current. 
     
     
         17 . The system of  claim 16 , wherein a total inrush current of charging the loading circuit is controlled to approach the maximum inrush current by the first charging current. 
     
     
         18 . The system of  claim 11 , further comprising:
 a second sensor;   wherein the second sensor senses a second charging current from the high voltage terminal to the loading circuit, and when the second charging current starts to drop, at least one additional power switch is turned on.   
     
     
         19 . The system of  claim 11 , wherein the first sensor generates a first message for turning on the at least one first power switches, and the first sensor generates a second message for turning on the at least one second power switches. 
     
     
         20 . The system of  claim 11 , wherein the at least one first power switches and at least one second power switches are multi-threshold complementary metal-oxide-semiconductor (MTCMOS) power switches.